Lubricating oil composition



C. O. TONGBERG FAL LUBRICATVING OIL COMPOSITION Jung 15, 1954 Filed Sept. 4. 1951 Humon'Y @Asma-r Lupe, (Houses) Gc1rlO.Ton..gberq @Inventors Wiliam Hruqmanmr.

E mbzwttof Patented June 15, 1954 2,681,315 LUBRICATING OIL COMPOSITION Carl O. Tongberg,

Westeld, and William H.

Brugmann, Jr., Elizabeth, N. J., assignors to Standard Oil Development Company, a corpo- 1 ration of Delaware Application September 4, 1951, Serial No. 245,058

14 Claims. 1

The present invention relates to a composition comprising a major portion of a lubricating oil and minor portions of rust preventive and detern gent additives.

It is known to the art to employ oil-soluble petroleum sulfonates and oil-miscible alkaryl polyether alcohols in combination in lubricants to render the oil relatively non-corrosive to metal parts. Such a composition aords protection under certain conditions against corrosion or rusting by moisture and aqueous solutions of electrolytes. it is frequently desired to use oilsoluble calcium petroleum sulfonates in oils since they are extremely eiective as engine oil detergent additives; however, calcium sulfonates, used in combination with a polyether alcohol, do not give the desired degree of protection from rusting required in certain types of oils. In addition, Calcium petroleum sulfonates and alkaryl polyether alcohols are not always compatible with one another. Haze formation occurs in many cases when these particular additives are employed in combination, and the haze does not disappear even upon prolonged standing.

It is also known in the art to compound oils with small amounts of a metal salt of an alkyl phenol sulfide and an oil soluble salt of a petroleum sulfonate to prepare lubricating compositions havng desired detergent andnon-corrosive properties. Such compositions, however, do not give the desired protection from moisture corrosion for certain types of uses.

It has been found that unexpectedly improved anti-rusting properties are imparted to a lubricating oil, preferably a mineral oil, by compounding with it at least three different components, each component being added in relatively small amounts. These components include a Waterinsoluble, oil-miscible alkaryl polyether alcohol, an oil-soluble calcium petroleum sulionate, and an alkaline earth metal salt of an alkyl phenol sulde.

The alkaryl polyether alcohol is an alkylphenoxypolyethoxyethanol having from two to six ether groups. Preferred compounds of this class are illustrated by the formula:

@ommenlohomcmon wherein R and R are selected from the class consisting of hydrogen and alkyl radicals having 4 to 12 carbon atoms, x is 1 to 5, and the polyethoxy radical is straight chain. The alkyl radicals should be of suiicient size and number to im" part oil solubility to the compound and may be lbutyl, amyl, hexyl, octyl, nonyl, dodecyl and the like, either the straight or branched chain configurations being useful. The phenoxy radical preferably has no more than two alkyl groups. When the aryl radical has only one alkyl group, it may be positioned in the ortho, metaor paraposition with respect to the polyether group. An octyl radical, particularly a tertiary radical, such as that derived by alkylation with diisobutylene, is very effective in the practice of the present invention. Preferably, the alcohol derivative contains ve ether groups and only one alkyl group.

The polyether alcohols are conveniently prepared by methods known in the art. An alkylated phenol is reacted with from two to six mols of ethylene oxide in one method of preparation. In another, it is convenient to react the alkylated phenol with an alkyl halohydrin such as triethylene halohydrin in the presence of a base.

The polyether alcohol may be used in the composition in concentrations as low as about 0.05%, preferably above 0.1 Weight per cent, and up to the limit of the solubility of the compound in the oil being used. The size and number of alkyl groups in the polyether alcohol will determine to a large extent the solubility of the compound in the composition. Generally the upper limit of solubility will be in the order of about 3 to 4%. A preferred range will be from about 0.2 to 2% by weight of the polyether alcohol based on the total composition. v

The oil-soluble calcium petroleum sulfonates used in the present invention are the salts of oil-soluble or so-called mahogany acids. They may be prepared by neutralizing acid treated oils or extracted sulfonic acids directly with a stoichiometric amount of calcium oxide or hydroxide. However, it is often more convenient to prepare them from the sodium salts by double decomposition. Particularly advantageous also are calcium petroleum sulfonates having an excess rather than a stcichiometric amount of calcium added to the sulfonic acid. Calcium sulfonates having an excess of calcium may be prepared by the procedure described in U. S. Patent N o. 2,467,176 to Zimmer, Carlson and Duncan. The term oilsoluble calcium petroleum sulfonates, as used in the present specication and claims, refers to both of the above general types of calcium sulfonates.

The molecular Weight of the calcium sulfonates may vary from about 750 to as high as 1100, al-

- 3 though as a Ygeneral rule it is preferred that the sulfonates have a molecular weight in the range of 800 to 1000. The sulfonates may be used in the finished composition in amounts ranging from about 0.4 to as high as 10.0 weight per cent on a dry basis. Preferably, the sulfonates may be used inarnountsranging from 0.5 to'. 45% by weight based onk the total composition. and in many cases amounts of from 0.5 to 2% will be entirely adequate to impart the desired deter.- gency characteristics to the nnishedoilandto cooperate with the other additivesv in improvinn the anti-corrosive properties of. the oil.

, The alkaline earth metalsalts ofyalkylphenoli suliides Vare well known as being effective` de'-l tergents and sludge dispersers for lubricating oils. ForV example, the preparation of calciumsaltsfof .Y this type, and their use in lubricants, is described in the Mikeska patent U. S. 2,362,289. The prepv aration of barium salts is described in the Winning patent, U. $12,362,291. rIjhe..--rnagnesiuni salts are described in thefMcNabfpatent; U..- S. 2,362,292,` and mixedalkalineV earth salts ,contain` ing tvvodiierent alkaline-"earth metals 'are described and claimed in U. S. 2,480,664 to-McNab', McNulty and Cross.

In the .present invention, the alkaline. earth' metal salts of alkylated phenol suldes haveat least one alkyl group attached to each benzene nucleus. The alkaline earth metals include calcium, barium, strontium, and magnesium. The presence of at least one alkylY group in .the/bene zene nucleus is necessary toimpart oil solubility tothe compound. The alkyl groups should contain at least 4 carbon atoms each and preferably The renewing. examples w01 illustrate the advantages of the present invention.

EXAMPLE 1 A1 series of-blends were prepared employing as base stock an SAE 30 grade motor oil derived from. a. solvent extracted MidContinent crude fraction. The blends included as additives tert.-

octyl phenyl ether alcohol having 5 ether groups 1 (additive l) alone and inv combination with either bariumtert-octyl phenol sulfide (additivefZ) or calcium petroleum sulfonateshaving an average' molecularr weight of about 950. Other blends included combinations of additive 2 and calcium petroleum sulfonateand vof these materials with additive 1.

The'blends were tested by coating standardV steel panels with the oil and placing the panels in a standard humidity cabinet maintainedat atemperature of 100 F., and a relative humidity of 100%. The time in hours requiredtorust the panels in the cabinetfis termed thehumidity cabinet life'. The tendency 'of the blends toform haze was also noted. Results of tests in Table I below:

Table I .-Adclitioes used in SAE 30 base sto-ck Addie Calcilm Vgio Adem H 'any Ve 1 Ve Ve' uml Biene N0..- P t) Suttlate C21 l l P1 (Wmv Egt-ggg?" Lofnia erccn a cium ercen ers.

pement) Sulfonate o o 0.5 1. 3s o w 0.5 3 0 0. 61s Y 0 0.5 48 0 0. 61s` 0 0.5 1. as o. 61s 2. 22 0 3 0. 55, 1. 241 0. 44. 0. 28s 1. o. 82s 1. aiV o. 5 2ss 1. 38 0. 61s 2. 22 0. 5 28s 1. asf 0; 61s 2. 22 0. 5 240 1. 3s 0. 61s 2. 22 0. c 264 1.65 0.413 4.00 0. 5- 16s should contain fromv 4 to 12 or more carbon atoms.. The alkyl radicals-may be straight chain or branched. The scope of thelinvention is not limited as to the number interconnect the benzene nuclea, but compounds containing from 1 toe-sulfur atoms in suchlinkage are preferred. The suliide may contain only Y one-alkaline earth metal, or may include a mixture of two alkaline earth metals. Bariumis the preferred' metal when the `sulde contains only ,one alkaline earth metal, but it is preferredin saltsof the phenol sulde andto thehighmetalof sulfur atomswhich f Additive 1 alone or in combination with either calcium sulfonate or additive 2 gave substantially no or only fair protection in the humidity cabinet test whenA using relatively low concentrations of theV additives. The combination ofcalcium sulfonate and additive 2 likewise gives no protection. However, by combining all three'- additives, an unexpected increase in` humidity cabinet life was realized. Indeed, a synergistic eiiect is achieved since the relatively Vgood Cabinet life of the blend, containing calcium sulfonate and alkaryl polyetlier alcohol is increasedy over vlive times by addition of -a small amount of barium tert.-octyl phenol kSulride,.a compound which even in combination with the alkaryl polyether alcohol gives no particular rust protection in a humidity cabinetas indicated by blend2. A haze resulted in the oil when using only calcium sul fonate and polyether alcohol (blends 3 ande) whichdid not disappear even afterstandingfor. one Week. No haze-=formation occurredwhen are shown the barium tert.octyl phenol sulde was used with the other two additives.

The relations between weight ratio of additive 2 to calcium sulfonates and humidity cabinet life for the blends containing 0.5 weight per cent of the polyether alcohol are shown in the graph in Fig. l of the accompanying drawing. Blends having a humidity cabinet life above about 190 to 200 hours were obtained at Weight ratios in the range of about 0.1 to 3.5. Generally, it is preferred that the concentration of calcium sulfonates be above about 0.5 weight per cent of the total blend in order to obtain the desired protection against moisture corrosion.

EXAMPLE 2 A series of blends similar to those made in Example 1 were prepared by using an SAE 30 base oil, and a mixed calcium-barium salt of tert.- octyl phenol sulde (a iditive 3) was used in place of the barium salt. The salt contained about 75 wt. per cent calcium and 25 wt. per cent barium based on the total metal content of the compound. The calcium sulfonate and alkaryl polyether alcohol (additive 1) used in these blends were identical to those used in Example 1. Results are shown in Table II:

Table H.-Addz'tzves used in SAE base stock lubricant fraction, considerable haze was formed which did not disappear after standing for one week at room temperature. In the other case, with an oil derived from a conventionally propane and cresylic acid solvent extracted Mid- Continent fraction slight haze formation occurred. In both cases, haze disappeared only after adding a small amount of metal phenol sulde. It is seen that the extent of haze formation Will'vary depending on the type and treatment of the base oil.

The lubricating oil base stocks used in the compositions of this invention may be straight mineral lubricating oils or distillates derived from paraiiinic, naphthenic, asphaltic or mixed base crudes, or if desired, various blended oils may be employed as well as residuals, particularly those from which asphaltic constituents have been carefully removed. Hydrogenated oils or White oils may be employed as well as synthetic oils prepared, for example, by the polymerization of olefns or by the reaction of oxides of carbon with hydrogen or by the hydrogenation of coal or its products. In certain instances cracking coil tar fractions and coal tar or shale cil distillates may also be used. Also for special ap- A combination of the mixed metal phenol sulfide (additive 3) and calcium sulfonates in different ratios gave some protection, but, by adding a small amount of additive 1, the humidity cabinet life was increased very appreciably.

EXAMPLE 3 plications, animal, vegetable or sh oils or their hydrogenated or voltolized products may be employed, either alone or in admixture with mineral oils.

'I'he lubricating oils may vary considerably in viscosity and other properties depending upon the particular use for which they are desired, but they usually range from about 40 to 150 seconds Saybolt viscosity at 210 F. For the lubrication of certain low and medium speed diesel engines, the general practice has often been to use a lubricating oil base stock prepared from naphthenic or aromatic crudes and having a Saybolt viscosity at 210 F. of 45 to 90 seconds Table IIL- Additives used in SAE 30 base stock C lcium Wt. Ratio, Additive Suifonate Additive Additive Humidity Blend No. 2 (Wt. t C 2t1o 151 (Wti Igfablet Percent) Percent) Suallgiie ercen e, rs.

It is seen that alkaryl polyether alcohols having three ether groups have substantially the same potency in rust inhibition as those With five ether groups.

EXAMPLE 4 Two different SAE 30 grade motor oils were blended in each case with 0.5 weight per cent of additive 1 (Example 1) and 1.05 weight per cent of calcium petroleum sulfonate. In one case, where the oil was derived from a conventionally phenol solvent extracted Mid-Continent 2*,581; are

' asvgraph-ite; or zinc oxidef. etc.

Ylwhatfis claimed, is: f

l. Aicompositionk of matter comprising-a major Y amount` ofY a mineralv lubricating; oil and, based onftotal composition',` about'.0-.4 tol r101% byl weight of calcium petroleum sulfon-ate, about 0.05V .to 4% by; Weight of an oil .miscible alkylphenoxypolyethoxyethanol having irorny two-l tu` sixv other gronpaand 0'.2.tc,10% by Weight ofV analkaline earth :metal zsalt oan :alkyl `phenol sulfide.

2-.A'compositiorrgoimatter comprising a major amount, based.A on -total. composition, of a mineral lubricating. eilandrustinhibiting amounts of about .0.4to. 10% by AWeight of an oil-soluble, calcium petroleum sulionateabout 0.2,to 10%7 by weightoi an alkaline earthmetal salt of an alkyl phenol sulfide; and about 0.05 to 4% by Weight organ alkaryl polyether'alcohol'having the formula: y

omn'zcnz'onomcngon' consisting of hydrogen and alkyl radicals having..

sulfide containing., at. 'least one` alkalinef-earth metal.

7. A non-rusting,haze-free:lubricantrcemposition comprising essentially amajor proportionof amineral lubricating'oilan 0.5 tot 5% oan oil-f soluble calcium petroleum sulfonaterhavingfamo.-

lecular wel v ht in the range of 750 to 11100 from i of an alkaline learth metal salt, 0fan suliide, and from 0.2 to 2.0% ,-ofga 0.5 to 5% alkyl. phenol compound having theiormula:

omonionomomon:

wherein R and R' are selectedvirom the group consisting of hydrogen and alkyl radicals hav,- ing 4 to l2 carbon. atoms and at least one R4 is an alkyl radical and n: is from 2te 4.

8. A composition in accordance With.claim;7 in which said` alkyl radical isztertfoctyl.

9. A composition in accordance with. claim `7 in which said alkaline earthA metalpis'barium.

10.. A composition in accordance with claimw 7 inwhich said alkaline earth metalpis calcium'.V

11. A composition in accordancewith-cla'imj'l in which said alkaline earth 'meta-l' is amixtureof calcium .and barium.

4 to 12 carbon atoms and at least one R is an alkyl radical and a: is from l to 5.

' 3. Composition in accordance with claim. 2 which said sulfonate has a molecular Weight in the range of 750 to 1100.

4. A composition comprising a major proportion of a mineral lubricating oil and, based onY total composition, about 0.4 to 10% oilfsolublevcalcium petroleumr sultonate, about 0.05. to 4% by weight of..analkylphenoxypoly ethoxyethanol..having.one. alkyl grouper 4to 12 carbon atoms and from 1 to 5 ethoxy groups, and about 0.2v to 10% by Vweight of an alkaline earth metal' salt or an alkyl phenol, suliide, saidsulfide ,and sulfonate being presentv in-a Weight ratio inthe range of 0.1 to 3.5.

5. A composition in accordance' with claim 4 in which said alkyl group is tertfoctyl.

6; A lubricant comprising a major proportion of a` mineral lubricatingxoil and.0.4;ft.o 10%..of .I an; oil-soluble; calcium petroleum, sulfonate, 0.1

to. 3.0% of; anVr oil-solubler alkyl-phenoxypolyethoxyethanolghaving from. 1 tol 5 ethoxy groups, and from 0.2 to 10% of a salt of an alkyl phenol by Weight of., an.

v in which said alkyl phenol sulfide is 12.` A composition inacoordance with. claimjl in which the Weight ratio of said alkyl phenol sulide salt to said calciuml sulionate is inv the range of 0.1v to 3.5`

13. Acomposition in accordance with claim 'l 'inn which said alkyl phenol suldeN is barium tertfootyl phenol sulfide.l

14. A composition in accordance with claim .7

a mixed calcium and barium salt oftertfoctylphenolsuliide.

References Cited inthe file of this patent UNITED STATES PATENTS, Y

Great Britain Jan. 28;..1949 

1. A COMPOSITION OF MATTER COMPRISING A MAJOR AMOUNT OF A MINERAL LUBRICATING OIL AND, BASED ON TOTAL COMPOSITION, ABOUT 0.4 TO 10% BY WEIGHT OF CALCIUM PETROLEUM SULFONATE, ABOUT 0.05 TO 4% BY WEIGHT OF AN OIL MISCIBLE ALKYLPHENOXYPOLYETHOXYETHANOL HAVING FROM TWO TO SIX ETHER GROUPS, AND 0.2 TO 10% BY WEIGHT OF AN ALKALINE EARTH METAL SALT OF AN ALKYL PHENOL SULFIDE. 